Which one of the following words/phrases is most appropriately used to denote "an interoperable network of 3D virtual worlds that can be accessed simultaneously by millions of users, who can exert property rights over virtual items"?

The Metaverse is the correct term as it represents a persistent, immersive 3D digital environment where users interact as avatars and exercise ownership through blockchain-based property rights. While "Virtual matrix" might sound plausible due to its science-fiction connotations, it is not a recognized technical or industry term for this specific interoperable infrastructure. This question tests the core concept of Web 3.0 and the evolution of digital social and economic spaces.